Path of Darkest Rage

Darkness is in everyone, even when they don't know about. Every battle, death, and swing is us channeling our desire to hurt or kill and some are okay with that. You on the other hand, learned that you don't have to be control by that kind of darkness and understand that the darkest things are in people own life and soul. It will not let go of you and will always be in you waiting to be release, and when it does it will do what it want. We often work to repress this part of ourselves, trying in all of our actions to deny they even exist. But you know that there is darkness is inherently valuable in that it provides the contrast to our light. You embraced that darkness because that is you going in battle and trying to achieve the goals that you made that you made for yourself and to have a understanding to yourself.

Umbra

At 3rd level, you learn to channel the darkness within you. You instinctually learn a ritual that creates a magical bond between yourself and one weapon. You perform the ritual over the course of 1 hour, which can be done during a short rest. The weapon must be within your reach throughout the ritual, at the conclusion of which you touch the weapon and forge the bond, which creates a dark seal upon it.
Once you have bonded a weapon to yourself, you can't be disarmed of that weapon unless you are incapacitated. If it is on the same plane of existence, you can summon that weapon as a bonus action on your turn, causing it to teleport instantly to your hand.
You can have up to two bonded weapons, but can summon only one at a time with your bonus action. If you attempt to bond with a third weapon, you must break the bond with one of the other two.

Additionally, you can channel Umbral Fury into your weapon strikes. While you're raging, your strikes become fueled by darkness. Creatures you hit on each of your turns with a weapon attack takes additional necrotic damage equal to your proficiency bonus + half your barbarian level.

Umbral Fury

When you rage, the darkness within you turn your clothes, skin, hair, and weapon become ink black, with glowing red eyes which leaves a flaming reddish Black fire when you move or strike. Your  instincts is heighten which allows feel the darkness in people and you are protected by your own darkness. You gain resistance to necrotic and have Blindsight with the range of 30 ft.

Rising Tension

The Darkness within you grows in power by making your weapon more powerful and helping to protect you, causing the Bonded weapons and your Umbra to count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage. Your darkness protects you from being hit by using your already bonded weapon. You can use your Bonded weapon to block by using your reaction to add your proficiency bonus to your AC for that attack, potentially causing the attack to miss you.

The Absents in Between

At level 10, the Tenebrosity of you has Darken even more when you rage, to the point it looks like you where somewhere else. You can teleport up to your proficiency Bonus X 10 feet to an unoccupied space you can see. Until your rage ends, you can activate this power of darkness again on each of your turns as a bonus action.

Darko Revenge

Darkness lash out of out of you as you have been hurt by a attack from your opponent causing a nasty explosion of necrotic energy to them. At level 14, using your reaction when you are raging ,an small orb necrotic energy with a shade of yellow will appears in front of the creature that attacked you within 60 ft. The creature must make a Dexterity saving throw. It takes equal to half your proficiency modifier d10 Necrotic damage on a failed save, or half as much damage on a successful one. The DC saving throw 8+twice your proficiency Bonus.